Device for feeding pressurized fluid

ABSTRACT

This invention relates to a device for feeding pressurized fluid to at least two supply circuits by two groups of pumps, the first group of pumps, of the variable discharge type, comprising two distinct delivery conduits and a power regulator of the pressure summation type coupled with the member for controlling the discharges of said first group of pumps, while the second group of pumps is of the constant discharge type, the second group of pumps comprises a single delivery conduit and the first delivery conduit of the first group of pumps and single delivery conduit of the second group of pumps are connected to the first supply circuit, while the second delivery conduit of the first group of pumps is connected to the second supply circuit.

United States Patent 1191 Praddaude [4 Mar. 12, 1974 [5 DEVICE FORFEEDING PRESSURIZED 3,535,877 10/1970 Becker @6111 60/427 FLUID3,543,516 5/l969 Treichel 60/427 3,720,059 3/1973 Schurawski.. 60/42]Inventor: Pierre Praddaude, 3,723,026 3/1973 'Soyland 417/216Crepy-en-Valois, France [73] Assignee: Societe Anonyme: Poclain, Oise,Examiner-William Freeh France 22 Filed: Aug. 3, 1972 it l Z f f 18mventlon re ates to a evice or ee mg pressur- [21 1 Appl 277534 izedfluid to at least two supply circuits by two groups of pumps, the firstgroup of pumps, of the variable dis- [30] Foreign Application PriorityData charge type, comprising two distinct delivery conduits Aug. 6, 1971France 7128969 and a Power regulator Ofthe Pressure summation typecoupled with the member for controlling the dis- 52 us. 01.... 417/216,417/426. Charges of Said fitst of Pumltt white the 511 Int. Cl. F04b23/04 group ofPump-t is of the Constant discharge type the 58 Field OfSearch 417/216, 426, 427; 60/421, secottd group of Pumps Comprises aSingle delivery 6O/427 conduit and the first delivery conduit of thefirst group of pumps and single delivery conduit of the second [56]References Cited group of pumps are connected to the first supply cir-UNITED STATES PATENTS cuit, while the second delivery conduit of thefirst group of pumps is connected to the second supply cir- 2 O98,425 ll/l937 Lautenberger 60/427 Quit 2,646,755 7/l953 Joy 9l/497 2,979,9084/1961 Shook.- 60/421 3 Claims, 2 Drawing Figures DEVICE FOR FEEDINGPRESSURIZED FLUID The present invention relates to a pressurized fluidfeed device. I

Prior art device .such as described in the U. S. Pat. No. 3,635,600,enables a very advantageous functioning to be obtained. In particular,the regulation of power of two groupsof pumps leads to the possibility,shown at the time, of using pumps with limited power, despite theexistence of circuits that may receive high powers.

The adjustment of the variation of the discharge of the pumps,particularly that of the discharge of the second group of pumps ispeculiar to the type of pump in question since it is possible to adopt,for the second group of pumps the constant discharge type of pump.

The present invention is advantageous as it permits a satisfactory feedof pressurized fluid to particular receiving members having suchfunctions that, in order to carry them out, it is often preferable, ifnot indispensable, for said receiving members to be fed at constantdischarge.

Furthermore, in those cases where it is desired to obtain a pressurizedfluid feed at constant discharge, the elimination of the power regulatorfor the second groups of pumps and the adoption, for this second groupof pumps, of constant discharge pumps, are factors of such a'nature asto reduce the cost price of the overall pressurized fluid feed device.

It will be noted moreover that, in view of the abovementioned advantage,inherent in the construction of the device comprising two powerregulators such as described U. S. Pat. No. 3,635,600, according towhich construction the pumps may be chosen to have moderate powers, theabsence of a regulator for the second group of pumps as revealed by thepresent invention does not cause any substantial disequilibrium of thefeed of the receiving members when certain of said receiving members areor are not fed at constant discharge. However, it will then be noted,that even in the supply of circuits not having receiving members whichhave to be fed at constant discharge, a lower cost price is obtained.

The reasons which have just been evoked have therefore led to providinga new feed device, which contains certain functional advantages and anadvantageous cost price.

The invention therefore has for its object to provide a device forfeeding pressurized fluid to at least two supply circuits via two groupsof pumps wherein the first group is of the variable discharge type withtwo distinct delivery conduits, while a power regulator of the pressuresummation type is coupled with the member controlling the discharges ofthe said first groups of pumps. The second group of pumps contains asingle delivery conduit. Thefirst delivery conduit of the first group ofpumps and the single delivery conduit of the second group of pumps areconnected to the first supply circuit, and the second delivery conduitof the first group of pumps are connected to the second supply circuit.

In this feed device, the second group of pumps is with constantdischarge, while a receiving device is disposed on the single deliveryconduit of said second group of pumps.

According to a first embodiment of this invention, the receiving deviceis interposed on the single delivery conduit between the connections ofsaid single conduit on the one hand to the secondgroup of pumps while onthe other hand to the first'delivery conduit of the first group ofpumps.

A distributor is advantageously disposed on the first delivery conduitof the first groups of pumps and ensures at least the communicationofthe first delivery conduit of the'first group of pumps selectively withthe first supply circuit, and with a third supply circuit.

According to a second embodiment of this invention and where theabove-mentioned distributor is provided, the receiving device isdisposed on the single delivery conduit beyond the connection of thefirst delivery conduit of the first group of pumps with said singledelivery conduit.

Finally, in the preferred applications of the abovementioned device, thereceiving member has a function for which, in order to carry it out, itmust be supplied with pressurized fluid at a constant discharge.

The invention will be more readily understood and secondarycharacteristics as well as their advantages will appear in the course ofthe following description of an embodiment given by way of non-limitingexample. Reference will be made to the drawings, in which:

FIG. 1 schematically shows a first embodiment of a feed device accordingto the invention.

FIG. 2 schematically shows a second embodiment of the feed deviceaccording to the invention.

Referring now to the drawings, FIGS. 1 and 2 show a first group of twovariable discharge pumps 1 and 2, which are grouped in an integralassembly 4. The pumps 1, 2 may moreover have an equivalent in a singlepump which would be constituted by the connection of the pumps 1 and 2in one casing. In the case of separated pumps 1 and 2, which is shown,the members 6 and 7 which control the discharges are connected by anarticulated connection 8. l

The pumps 1, 2 and a constant discharge pump 26 are provided with theirdelivery conduits respectively as shown in FIG. 1 at 9, 10a-10b and11a-l lb, and in FIG. 2 at 9, 10a-10b and 11. A two-way distributor 27is interposed between the parts and 10b of the conduit 10a-10b.Furthermore, a receiving member 28 is also interposed between the parts11a and 11b of conduit lla-l 1b. Pipes 12 and 13 are connected toconduits 9 and 10a, such as by welding, and connect said conduits 9 and10a to a power regulator 15 with pressure summation.

The power regulator 15 is a member which, as a function of the pressuresof the fluid in the delivery conduits 9 and 10a transmitted via thepipes 12 and 13, acts on the link 8 for controlling the discharge of thepumps 1 and 2. This regulator 15 limits the: power delivered to thesupply circuit to a determined value. The power regulator 15 may be ofthe pressure summation type such as disclosed in said US. Pat. No.3,635,600. It is the sum of the actions of the pressures prevailing inthe delivery conduits 9 and 10a which acts on the articulated link 8,thus on the members 6 and 7 for controlling the discharges of pumps 1and 2.

Furthermore, the delivery conduit 9 is connected to a supply circuit, ofwhich the inlet conduit 20 has been shown for example as a thimble orclamp 21. Conduit 10b connects the distributor 27 to the connectingthimble or clamp 23 which ensures the branching of the conduit 11b ofFIG. 1 or of the conduit 11 of FIG. 2 with said conduit 10b and with aso-called first supply circuit as shown by conduit 25. The conduit 20reprebers 28 and 29 are often members that have to be fed at a constantdischarge, for example jacks. In the example shown in FIG. 1, the member28 may be a jack controlling the steering members of a public worksmachine. In the example of FIG. 2, the member 29 may be one or morejacks used for maneuvering the operating equipment (jib beam-bucket) ofa public works machine. In the two examples mentioned hereinabove, the

circuits and/or 24 may be the hydraulic circuits feeding the translationmotors of the corresponding public works machine.

The advantage of having provided a feed capable of connecting thedelivery conduits of three pumps 1, 2, 26 to the two supply circuits 20and 25, associated with the existence of the regulator 15, residesessentially in the possibility of selectively choosing for pumps 1, 2and 26, for example, all of the power equal to a given power, said givenpower being relatively moderate.

When, in accordance with the invention, pump 26 is chosen as havingconstant discharge, and while retaining practically the same advantageas in the prior known circuits, which resides in the possibility ofobtaining an available power of the fluid conveyed in the conduit 25greater than that discharged by the single pump 26, the member 28, whichis constituted by a jack, may in addition be satisfactorily fed.

It is preferable in order to obtain a high precision of adjustment ofthe position of the element controlled by a jack, to feed said jack atconstant discharge. This in indeed the case shown in FIG. 1, in whichthe element controlled by the jack 28 may be the steering members of themachine, the position of which mechanism must be adjusted withprecision, if it is desired to obtain a satisfactory precision ofdisplacement of said machine during changes in direction. The directfeed of the member 28 by the constant discharge pump 26 thereforeenables the desired precision to be obtained.

With the device of FIG. 1, it may be desirable to have the possibilityof feeding a possible third circuit 24. This may be in fact realized bydisposing the distributor 27 in its second position.

Finally, with regard to FIG. 2, it will be noted that a receiving member29 may also be disposed on the conduit 25 downstream of the thimble orclamp 23 with respect to the pump 26. In this case, the member 29 may befed either solely by pump 26, when the distributor 27 is disposed in itssecond position, or by pumps 26 and 2, when the distributor 27 isdisposed in its first position. In this particular arrangement of themember 29 on the conduit 25, it is necessary to provide the distributor27 in order to be able effectively feed said member 29 only with thesingle pump 26, in the operational phases during which said member 29must be controlled with precision. This is particularly the case wherethe member 29 constitutes a jack or jacks for maneuvering the operatingequipment of the machine.

The preferred applications of the feed device which has just beendescribed reside in the concomitant feeds of receiving members, someunder possibly variable discharges, the others under substantiallyconstant discharges. It remains that, even for the feed of receivingmembers under any discharges, which are not necessarily constant, theapplication of the new device avoids having to choose a pump which wouldbe of variable discharge, and having to control said pump by a powerregulator. A considerable saving is therefore made.

Obviously, the embodiments shown are exemplary only and a wide varietyof embodiments may be devised without departing from the spirit andscope thereof.

What is claimed is:

l. fluid control system for feeding pressurized fluid to at least twosupply circuits, comprising:

a. at least two variable discharge pumps, each of said pumps having asingle delivery conduit, and means associated with said variabledischarge pumps and controlling the discharge of said pumps throughtheir respective delivery conduits;

b. a power regulator of the pressure summation type operatively coupledto said means, said power regulator being directly connected to each ofsaid respective delivery conduits;

c. at least one constant discharge pump having a single deliveryconduit;

(1. first, second and third supply circuits;

e. said second supply circuit being connected to said delivery conduitof a one of said at least variable discharge pumps;

f. a distributor connected between said delivery conduit of another ofsaid at least one variable discharge pumps and said first and thirdsupply circuits respectively, said distributor having at least twopositions whereby said delivery'conduit of another of said pumps isalternately connected to said first and said third circuitsrespectively; and

g. a receiving device connected between said single delivery conduit ofsaid constant discharge pump and said first circuit.

2. A system as defined in claim 1 wherein the distributor is connecteddirectly to said single delivery conduit of said constant dischargepump.

3. A system as defined in claim 1, wherein said distributor is connecteddirectly to said first circuit.

1. A fluid control system for feeding pressurized fluid to at least twosupply circuits, comprising: a. at least two variable discharge pumps,each of said pumps having a single delivery conduit, and meansassociated with said variable discharge pumps and controlling thedischarge of said pumps through their respective delivery conduits; b. apower regulator of the pressure summation type operatively coupled tosaid means, said power regulator being directly connected to each ofsaid respective delivery conduits; c. at least one constant dischargepump having a single delivery conduit; d. first, second and third supplycircuits; e. said second supply circuit being connected to said deliveryconduit of a one of said at least variable discharge pumps; f. adistributor connected between said delivery conduit of another of saidat least one variable discharge pumps and said first and third supplycircuits respectively, said distributor having at least two positionswhereby said delivery conduit of another of said pumps is alternatelyconnected to said first and said third circuits respectively; and g. areceiving device connected between said single delivery conduit of saidconstant discharge pump and said first circuit.
 2. A system as definedin claim 1 wherein the distributor is connected directly to said singledelivery conduit of said constant discharge pump.
 3. A system as definedin claim 1, wherein said distributor is connected directly to said firstcircuit.